In automatic beverage dispensers, there already exist different types with various infusion assemblies. These assemblies have complicated mechanical movements performed by electric motors and reducers, of high cost, as well as lever transmissions which must be very precise. These assemblies also require a very precise volumetric dosage of the coffee powder so as to avoid interfering with the movements and transmissions. It will be understood that the operation of such assemblies is delicate and require careful production and assembly of multiple mechanical pieces.
To overcome these delicate and difficult constructions, it has already been proposed to replace these motorized movements and lever transmissions with movements performed by double-acting hydraulic jacks. Unfortunately, this type of hydraulic jack is difficult to control, not only as to the movement of its piston, but also as to the equilibrium of the opposing pressures, and gives rise to prohibitive costs for automatic beverage dispensers, such as espresso coffee-making machines which must be mass-produced.